Er-doped LiNbO3 waveguide lasers

The state-of-the-art of Er-doped integrated optical lasers in LiNbO3 is reviewed. They are fabricated in Er-diffusion doped substrates with Ti-diffused channel guides of high quality. The laser resonators are formed by dielectric mirrors vacuum-deposited on the polished waveguide end faces. Five different types of Ti:Er:LiNbO3 waveguide lasers are presented. Among them are free running Fabry-Perot lasers of six different wavelengths in the range 1530nm < lambda < 1610nm with a cw-output power up to 63mW. They have a shot noise limited relative intensity noise (RIN) at frequencies above 50MHz. Tunable lasers have been developed by the intracavity integration of an acoustooptical amplifying wavelength filter yielding a tuning range up to 31nm. With an intracavity electrooptic phase modulator modelocked laser operation has been obtained with pulse repetition frequencies up to 10GHz; pulses of only a few ps width could be generated. With an intracavity amplitude modulator Q-switched laser operation has been achieved with of up to 2.4W pulse peak power (0.18 mu J) at 2kHz repetition frequency. Moreover, distributed Bragg reflector (DBR-) lasers of emission linewidth < 8kHz have been developed using a dry-etched surface grating as one of the mirrors of the laser cavity.